One of the main reasons we must read other writers in our genre is that we must know what is usual. Readers of a particular genre come to it with a set of expectations. You may tweak those expectations to make your work unique, but if you violate genre expectations too wildly, you will lose readers. Their expectations will not be met, and they will say so in their reviews.
☐ The amount of description is appropriate to the genre.
I recall an Amazon review in which the reviewer complained that the author of a thriller had spent too much time describing people’s clothes. At first, I didn’t understand why this is a problem, because I personally like that kind of description. I had to read several other reviews of that book and others like it before I figured out that it’s a genre convention.
I primarily read fantasy and historical novels. These are usually full of rich descriptions. Thriller novels are not. Thrillers are active, and the readers are less interested in what a character is wearing than in what he is doing. So in a thriller or similar action-oriented genre, you will give just enough description for the reader to get a picture, and then return to the main action. Because most thrillers are set in the present day, all you have to say is that, for example, the hero is wearing black jeans and a leather jacket, and move on. Readers of this genre don’t want to know the details about the buckles on his jacket or the style of his boots. If the hero walks into a bar, you don’t have to say much more than that unless it’s a really unusual bar.
Readers of historical, fantasy, and science fiction novels, by contrast, expect a lot of description because the world being presented is very different from our own. Think of the cantina in Star Wars IV: A New Hope. If you were writing the novel version, you couldn’t just write, “Luke walked into a bar.” You’d have to take the time to describe that scene almost as thoroughly as the camera does. Otherwise the reader will not have clarity about the scene.
In a contemporary novel, you might say a woman is wearing a green dress and leave it at that. But in historical or fantasy fiction, more description would be needed. Is her dress a straight shift, or an elaborate gown with a bustle and crinolines?
Conversely, thriller readers may be very interested in a description of the hero’s weapons. But in fantasy you can often get away with simply saying he wields a broadsword; in science fiction it might be a blaster. The readers understand these terms and will move on. Of course, the principle of proportion applies: The more important the costume or the weapon or what have you is to the story, the more description it deserves.
I’ve only used these genres as examples; there are many others, and whichever one you’re writing in, you need to know what’s customary so you know what the boundaries are. Feel free to stretch those boundaries, but don’t ignore them.